ABSTRACT
Background: Aberrant activation of phosphatidylinositol-3 kinases [PI3K]/AKT/mTOR [mammalian target of rapamycin] pathway is a critical event during gastric cancer progression. Selective function of AKT inhibitor AZD5363 in PI3KCA mutant gastric cancer necessitates the assessment of PI3KCA mutations in these patients
Methods: The study included 100 patients with gastric cancer who underwent surgical resection at Imam Reza Hospital, Tehran, Iran, between January 2009 and December 2016. Mutations in codon 1047 of PIK3CA were evaluated by tetra-primer ARMS-PCR and direct sequencing methods
Results: We detected p.H1047R and p.H1047L in eight and three samples, respectively. Also, a significant association was found between PIK3CA mutations and lymphatic invasion. Kaplan-Meier analysis demonstrated no significant differences in overall survival between patients with and without mutations
Conclusion: Our study detected gain-of-function mutations in exon 20 of PI3KCA gene in 11% of gastric cancer patients. Future studies are needed to assess the mutation rate in other regions of this gene to find eligible patients for targeted therapies
ABSTRACT
Background: Colon cancer-associated transcript 2 [CCAT2] is a newly recognized IncRNA transcribed from the 8q24 genomic region. It functions as an oncogene in various types of cancers including breast cancer, in which it affects Wnt/p-catenin pathway. Previous studies have shown a putative interaction between this IncRNA and MYC proto-oncogene
Methods: In the current study, we evaluated the expression of CCAT2 in breast cancer tissues with regards to the expression of its target MYC. In addition, we assessed the relationship between CCAT2 and MYC expression levels in tumor tissues and the clinical prognostic characteristics of breast cancer patients
Results: MYC expression levels were significantly up-regulated in tumor tissues compared with adjacent non-cancerous tissues [ANCTs], while such analysis showed no statistically significant difference between these two tissue types in CCAT2 expression. Starkly increased CCAT2 gene expression levels were found in 12/48 [25%] of cancer tissue samples compared with their corresponding ANCTs. Furthermore, significant inverse correlations were found between CCAT2 expression and stage, as well as lymph node involvement. Besides, a significant inverse correlation was found between the relative MYC expression in tumor tissues compared with their corresponding ANCTs and disease stage
Conclusions: These results highlight the significance of MYC and CCAT2 expressions in the early stages of breast cancer development and suggest a potentially significant role for CCAT2 in a subset of breast cancer patients, which could be applied as a potential therapeutic target in these patients